ABSTRACT This study was to investigate the neuroprotective effect of curcumin against inflammation-mediated dopaminergic neurodegeneration in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mice model of Parkinson's disease (PD). Curcumin loaded sodium hyaluronate based mucoadhesive microemulsion (CMME) was developed by using Box Behnken design of Response surface method (RSM) and was characterized. Male C57BL/6 mice were first treated with four intraperitoneal injections of MPTP (20 mg/kg of body weight) at 2 h intervals followed CMME intranasal administration for 14 days at 2.86 mg of curcumin/kg of body weight per once a day. Optimal CMME containing 3% Capmul MCM as oil phase, 37 % of Accenon CC and Transcutol HP at 2.

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1 ratio and 0.5% sodium hyaluronate was stable, non-ciliotoxic with 57.66 nm±3.46 as average globule size. PdI value (0.190 ± 0.19) and TEM result depicted the narrow size distribution of CMME.All three independent variables had a significant effect (p<0.05) on the responses and the designed model was significant for all taken responses. In-vivo results revealed significant reduction of MPTP-mediated dopamine depletion after nasal administration of CMME. MPTP intoxication significantly decreased striatal DA content to 21.29 % which was then elevated to 55.37% after intranasal curcumin treatment. Significant improvement in motor performance as well as gross behavioural activity of mice was observed from rota-rod and open field test findings. Findings of the investigation revealed the symptomatic neuroprotection of curcumin against MPTP-induced neurodegradation in the striatum and hence could be considered as a promising approach to treat PD.